# CVE-2026-45929: ovpn: fix possible use-after-free in ovpn_net_xmit

> A use-after-free vulnerability in the Linux kernel's ovpn module allows attackers to potentially execute code or cause a denial of service.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 27 May 2026
- **Updated:** 5 Aug 2026
- **Also known as:** BELL-CVE-2026-45929, DEBIAN-CVE-2026-45929, GHSA-54qr-3h8v-g6xr, UBUNTU-CVE-2026-45929

## What is CVE-2026-45929?

CVE-2026-45929 is a high-severity use after free vulnerability in Linux kernel, published on 27 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

ovpn: fix possible use-after-free in ovpn_net_xmit

When building the skb_list in ovpn_net_xmit, skb_share_check will free
the original skb if it is shared. The current implementation continues
to use the stale skb pointer for subsequent operations:
- peer lookup,
- skb_dst_drop (even though all segments produced by skb_gso_segment
  will have a dst attached),
- ovpn_peer_stats_increment_tx.

Fix this by moving the peer lookup and skb_dst_drop before segmentation
so that the original skb is still valid when used. Return early if all
segments fail skb_share_check and the list ends up empty.
Also switch ovpn_peer_stats_increment_tx to use skb_list.next; the next
patch fixes the stats logic.

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2026-45929?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-45929?

Apply the vendor's patch.

## Is CVE-2026-45929 being exploited?

There is no known exploitation of CVE-2026-45929 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-45929 and fix it if it is affected.

What it is: CVE-2026-45929 is a high-severity use after free vulnerability in Linux kernel, published on 27 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-45929 in the wild and no public exploit code.

Affected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-45929/ (Markdown: https://insights.sbomify.com/CVE-2026-45929/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-45929
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-45929
- OSV: https://osv.dev/vulnerability/CVE-2026-45929

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-45929/
Summaries are generated and may contain mistakes; the official description above is the record.